DESCRIPTION (provided by investigator): Gestational weight gain (GWG) is a potentially modifiable risk factor for a number of important maternal and infant health outcomes. In 2009, the Institute of Medicine (IOM) Committee to Reevaluate Gestational Weight Gain Guidelines published resubmitted weight-gain recommendations. However, the resubmitted guidelines were established without a clear understanding of their impact on a number of important outcomes such as stillbirth, infant death, child neurocognitive status, preeclampsia, and long-term maternal and offspring obesity. Further, the IOM committee highlighted the importance of assessing pattern and timing of GWG in addition to total GWG. This application directly responds to those research needs by examining the influence of total GWG and pattern of GWG on a broad range of short- and long-term maternal and offspring outcomes. Our study design will employ existing electronic records from two retrospective cohorts (124,590 singleton births at Magee-Women's Hospital in Pittsburgh, Pennsylvania and 36,384 singleton births at Alta Bates Summit Medical Center in Berkeley, California), as well as data from a prospective cohort of 471 mother-child dyads born at Magee-Women's Hospital and followed for 22 years. This project seeks to determine the association between total GWG and 12 adverse outcomes for mothers (gestational diabetes, preeclampsia, and maternal postpartum body mass index change at 22 years postpartum) and offspring (stillbirth, infant mortality, spontaneous preterm birth, small- and large-for-gestational-age births, neurocognitive deficits, child obesity at age 6 adult obesity at age 22). To study this association, an innovative method to assess total GWG will be developed that removes the bias in the existing measures' correlation with gestational length. This project will also examine the relationship between maternal GWG trajectory and adverse perinatal outcomes. A novel growth curve analysis method will be used to determine the independent contribution of timing, amount, and velocity of GWG to poor pregnancy and birth outcomes. The successful completion of these aims will fill major gaps in knowledge about the weight gain ranges and patterns associated with optimal maternal and child health. The use of innovative methodology combined with the ability to study multiple adverse outcomes simultaneously will advance our understanding of GWG in an effort to inform future evidence-based guidelines. Our use of two diverse cohorts will increase our study's generalizability and potential to impact medical practice and public health policy.